Roberto Mancini believes Manchester City made a mistake by not signing another defender in the January transfer window and said they would have bought someone had they known the full extent of Vincent Kompany's calf injury.
The City captain, who was injured in the FA Cup win at Stoke on January 26, is still yet to return and has been ruled out of Saturday's trip to Everton, meaning he will have been out for more than two months by the time they next play.
But while Mancini has denied Kompany will be out for the season, he had expected the Belgian, who has now resumed light training, to be available weeks ago.
In Kompany's absence, Kolo Toure has become Matija Nastasic's regular partner in the centre of defence and City have kept four consecutive clean sheets.
However, before that, they conceded five goals – and lost five points – in the 2-2 draw with Liverpool and the 3-1 defeat at Southampton, which could end up costing them the title. Toure, who was at the African Nations Cup, also missed both matches, with Mancini pairing his two left-footed centre-backs, Nastasic and Joleon Lescott, against Brendan Rodgers' team and selecting midfielder Javi Garcia in the back four at St Mary's.
And the 48-year-old rued City's failure to act in the final few days of the winter window, saying: "Probably we did a mistake because when we knew this problem we were four days to the close of the market. Probably then we should have bought another defender."
The Italian revealed that City had an opportunity to get reinforcements in defence, adding: "We had a chance because we had one good defender but we didn't think that Vinnie would stay out for 40-45 days."
Mancini believes that Kompany is finally on the comeback trail and is optimistic the defender will be available to face Newcastle on March 30.
He explained: "He has started to run and we hope that he will be ready for Newcastle. He started with us three or four days ago but he was tired because he worked a lot. But we don't want to take a risk at this moment because we have one game and after it is the international break. It is better we wait."